Combination incandescent and ultraviolet lamp



Feb. 6, 1940. E. MACKSOUD 2,189,508

' COMBINATION INCANDESCENT AND ULTRAVIOLET LAMP Filed Aug. 6, 1935 Michel MacKsoud ATTORNEYS Patented Feb. 6, 1940 UNITED STATES cor'rsnvs'rron mcsnnsscsn'r AND ULTRAVIOLET LAMP Michel E. Macksoud, St. Albans, N. Y., assignor Macksoud Patents, Inc., Ncw Yorh, N. Y., a corporation of New York Application August 6, 1935, Serial No. 34,884

3 Claims.

This invention relates to improvements in combination incandescent and ultraviolet lamps.

One of the objects of this invention is to provide in a single structure an incandescent lamp for illuminating purposes and an ultraviolet lamp for therapeutic purposes.

Another object of this invention is to provide in a single structure an incandescent lamp, and either a gaseous or vapor discharge lamp, for the purpose of producing a highly efficient white light combining the wide bands of spectrums obtainable from'both lamps, and causing the unit lamp to have a continuous spectrum, thereby improving its qualities of illumination.

An object of this invention is to provide devices of this nature in combination which may be operated from the ordinary 110 volt lighting circuit, either of the A. C. or D. C. type.

A still further object of this invention is to' A still further object of this invention is to provide an ultraviolet light source within several vessels transparent to ultraviolet rays to the substantial exclusion of the rays of shorter wave length at the lower end of the spectrum which have little therapeutic value and are probably harmful.

A still further object is to provide a device of this type in which the light source becomes incandescent instantaneously upon energization.

A still further object of this invention involves a construction in which a portion of the voltage drop in the high resistance incandescent filament is employed to establish a potential difi'erence between the electrodes in the mercury vapor chamber.

A still further object is to provide means for utilizing the voltage drop and resistance of the incandescent filament to build up the current flow in the mercury vapor are.

A still further object of this invention is to utilize the incandescent filament as the current limiting means for limiting the current in the mercury vapor arc.

These and many other objects, as will appear from the following disclosure, are secured by means of this invention.

' re-entrant stem l l This invention resides substantially in the combination', construction, arrangement andrelative location of parts, all as will appear more fully in the following specification, taken in connection with the patent drawing.

Referring to the drawing Figure 1 is a side elevational view of the device of this invention showing parts thereof in cross section; 7

Fig. 21s a diagrammatic illustration of the circuit arrangement oi. this device;

Fig. 3 is a diagrammatic illustration of a modifled form of circuit arrangement;

Fig. 4 is a diagrammatic illustration of a still further modification.

It is common practice in employing a mercury vapor arc lamp as a source of ultraviolet rays as a therapeutic agent to employ a current limiting device in order to prevent the current flow through the are increasing above desired and safe values. With the present invention the current limiting device is in the form of an incandescent filament, which, in addition to its current limiting functon. has the additional functions of producing useful light and providing heat for starting the mercury vapor arc. It is quite obvious that if an incandescent lamp can be provided in combination with a source of ultraviolet rays it would have great utility. I

The present invention combines in one structure suitable for operation from the ordinary 110 volt lighting circuit of either the A. C. or D. C. type a source of light and a source of'ultraviolet rays, producing as a result for therapeutic purposes not merely ultraviolet rays but in addition infrared or heat rays which are considered to be essential in attaining the full benefits of the ultraviolet ray.

The invention will now be described in detail in connection with the drawing. The device comprises a suitably shaped vessel or bulb i having the neck 2 mounted in a base 3. At 4 is the center contact which, in conjunction with the metal base 3, forms the terminals for the device. The

vessel I has a re-entrant stem, 5 terminating in a press 8 from which projects the standards or supports 8 and 9. Mounted on the supports 8 and 9 is a second vessel or tube it) having a hollow The vessels i and it are, of course, preferably made of a glass which is transparent to both visible light and ultraviolet rays.

' There are a number of known forms of glass of this type, most of which are 'sold under trade names. However, by way of example, quartz glass or-a quartz base glass is suitable for this purpose since it will transmit both visible light and ultraviolet light to the exclusion of the light of shorter wave length at the lower end of the spectrum which is considered to be harmful, or at least of no therapeutic value.

At 1 is an insulating spacer and support mounted in the neck of the vessel I through which the standards 8 and 9 pass. This insulating spacer also acts as a wall to prevent the transmission of heat from the main vessel which, in accordance with standard practice, contains argon, at a suitable pressure with which is preferably mixed, likewise in accordance with standard practice, a small amount of an inert gas, such as nitrogen.

Extending from the re-entrant stem ll of the vessel ID are two metal standards or' supports I2 and I2. Mounted on these supports are the electrodes of the mercury vapor lamp. These electrodes comprise cylinders. or sleeves H of a suitable metal, such as nickel, upon the outer surface of which has been deposited aucoating I 9 of electron emitting material in accordance with well known practice in the vacuum tube art. Mounted within the sleeves M are tubes I l of some suitable insulating material, such as a ceramic insulator, within the bores of which are mounted the coiled resistance heaters l8; The heater, of course, need not be coiled but may be straight filament wires of any suitable material, and, indeed, may assume any convenient form. The lower ends of the heaters are connected by the leads I1 and 8 to the conducting standards l2 and I2, respectively. At and 2| are perforated sleeves, grids or mesh cylinders which surround the sleeves N in close proximity thereto. These grids 22 and 2| act as electrodes and are connected respectively to the standards l2 and 2.

At 22 is an insulating support extending from the top of the vessel or tube III and suitably shaped and positioned to sup ort on the radiating arms 24 an incandescent filament 28 which is constructed in accordance with the well known practice in the incandescent lamp art and herein shown as being of the coiled type. One terminal of the filament 22 is connected by wire 21 to the conducting support 8 which in turn is connected by wire 28 to the center contact 4 at the base. The other terminal of the filament 22 is connected by'wire 28 to the conducting support I2. The other conducting support I2 is connected to conducting support 8, which in turn is connected by the lead 25 to the conducting metal base 2 thus completing the energizing circuit for the filament.

Within the vessel I0 is a small drop of mercury. indicated by the symbol Hg. Likewise within the vessel I0 is placed a small amount of an inert gas. such as argon, neon, krypton and the like. when the lamp is cold the pressure of the gas within the vessel l0 may be of the order of half a millimeter or more.

Fig. 2 illustrates diagrammatically the circuit arrangement of parts. as illustrated in Fig.1. As shown, the lead 28 is in direct connection with one end of the filament 22. The other end of this filament is connected by wire 28 to one end of one heating coil l8, which in turn is connected to one end of the other heating coil l8, which is finally connected to the other lead 25. As indicated in 'Fig. 2 the metal sleeve I I is connected to the lower end of. the heater coil l8 and to the grid electrode 20. In a similar way the lower end of the right hand heater coil 8 is connected to its sleeve i8 and to its associated grid, 2!.

In the operation of the device, when current is turned on it will flow in series through the heaters l8 and the incandescent filament 22. The heaters are proportioned in resistance to the filament 22 so that it will be energized sufiiciently to give of! useful light but will not be at its maximum incandescence at the start. As-the heater coils l8 heat up, the coating I! on the sleeves M will begin to emit electrons. These electrons will be drawn towards one or the other of the grids l8, depending upon which is more positive than the other. When energized with direct current one grid will, of course, always remain positive with respect to the other, but on the other hand when energized with alternating current the grids will be alternately positive with respect to each other. The potential impressed upon these grids will be represented by the voltage drop between the ends of the heater coils l8 since the grids are connected thereto as previously described. Thus the emitted electrons will be attracted to the more positive grid and their velocity will be sufiicient to ionize the inert gas content of the vessel II. In the meantime mercury vapor will begin to be liberated within the vessel l0 due to the heat supplied both from the heater coils I2 and particularly from the large incandescent filament 22. The ionizationpf the inert gas within the vessel II will aid in the developme'nt of ionization of the mercury vapor and this process will continue to build up until the mercury vapor within the vessel ll glows or until a mercury vapor arc is formed. This discharge will occur between the grid electrodes 28 and 2|.

At this point it should be noted that the grid electrodes are not absolutely essential since the discharge could occur between the coated metal sleeves I4. These grid electrodes are preferably used, however, to prevent the discharge between the coated electrodes, thereby increasing the life of the coatings |8 which otherwise would be rapidly destroyed. When the mercury vapor are has been fully built up it will provide a relatively low resistance current path between the grid electrodes 22 and 2|, thereby effectually short-cir- .cuiting the heating coils l2. As a result the current will then fiow (referring to Fig. 2) through the lead 28 to grid 2|, thence through the mercury vapor arc to grid 28 and from grid 28 through lead 28 to the incandescent filament and lack to the return side of the circuit through lead As a result, the heating coils l8 will be shortcircuited and the mercury vapor discharge will be self-sustaining. At the time that the heating coils l8 are cut out of circuit the filament 22 will come to full incandescence. The lamp is now generating both visible light and ultraviolet light so that a person sitting under it will be able to utilize them both. 7

In the arrangement shown in Fig. 3 the outer and inner vessels and I! are employed as before.

Within the inner vessel the electrodes are constructed as before, comprising metal sleeves H which may be coated with an electron emissive material, grids 20 and 2|, and heating coils It, all of which are electrically connected together as shown. The unconnected ends of the coil it are shunted across the leads 28 and 26 by the leads 20 and 2|, respectively. The metal sleeves ll are connected across a portion of the filament 22 by the leads 22 and 22 which also comprises a .part of the shunt circuit of the heating coils ll.

As before, there is mercury in the vessel It. In

' this case the potential diiierence between the grid electrodes 20 and 2| is provided by the potential drop of the portion of the filament 23 connected between the leads 32 and 33. When the mercury are forms between the grid electrodes the portion of the filament 23 between the leads 32 and 33 is shunted out of circuit.

With this arrangement, since the filament 23 is of very high resistance material, only a very small portion thereof is necessary to give the required potential difference between the grid electrodes..'I'he result is, therefore, that when this portion of the filament 23 is short-circuited the illumination from the filament as a whole is not materially decreased. Of course, in addition, the resistance of the coils it must be properly proportioned with respect to the resistance of filament 23 so when they are cut out of the circuit by the mercury arc discharge the brilliance of the filament will not change materially.

The arrangement of Fig. 4 is a somewhat simplified arrangement in which the electrodes id within the vessel l0 are, in, this case, in the form of solid metal rods which are shunted across a portion of the filament 23 by the leads ill and ii to provide the necessary potential difference between the electrodes to cause the device to oper ate. In this case the shunted portion of filament 23 is cut out of circuit when the low resistance mercury arc discharge builds up between the electrodes. Here, again, the brilliance of the filament does not materially change because of the relatively small portion of it which is cut out of circuit. The rods M need not necessarily be but preferably are coated with an electronically active coating.

For a gas pressure of the order of half a'miliimeter or more within the vessel Ill it is only necessary to provide a potential difference between the electrodes 20 and 2| of the order of about 15 volts. As is well known by those skilled ployed in the vessel ill in place of the mercury. With this arrangement the incandescent filament still acts as a current limiting device, as a light source, and as a heat source. The spectrum of a metal vapor of this type has no known therapeutic value but is of great value as it Such a light source, particularly light source. when generated from sodium vapor, has an intensity approximately four times greater than any other known light source. It is, therefore, Within the scope of this invention to employ the general principles thereof in connection with sodium and potassium vapors to provide an efficient light source.

From the above description it will be apparent that this invention resides in certain principles of construction and operation which may be em-.

bodied in other physical forms by those skilled in the art without departure therefrom.

I do not, therefore, desire to be strictly limited to 'the disclosure as given for purposes of illustration, but rather to the scope of the appended claims.

What I claim and seek to secure by United States Letters Patent is:

1. An electric lamp of the class described comprising an outer bulb having a filament of substantial length and high resistance therein, an inner tube having an ionizable gas content, and electrodes in said inner tube connected to said filament at points spaced substantially equal distances from and within its ends.

2. An electric lamp comprising an outer bulb having a filament mounted therein and an energizing circuit for the filament, an inner tube having an ionizable gas content, electrodes mounted in the tube and connected at spaced points to the filament, and heater coils for the electrodes shunted across a part of the filament circuit, a substantial portion of the filament being excluded from the electrode circuit.

3. An electric lamp comprising an outer bulb having a filament mounted therein'and an energizing circuit, an inner tube having an ionizable gas content, electrodes mounted in the tube and connected at spaced points to the filament to shunt out a relatively short portion thereof when an arc discharge is in operation between the electrodes, heater coils for the electrodes, and circuits therefor in which is included the electrode connections, a substantial portion of the filament being excluded from the heater coil circuits.

MICHEL E. MACKSOUD. 

